Smoking related cancer morbidity and mortality

The majority of people with cancer will initially present to general practice, therefore GPs have an excellent opportunity to make a difference with early detection and the initiation of speedy referral to specialist services. However, the difficulty is to achieve improved cancer detection without increasing unnecessary referrals, which may reduce access to services for people who need them.

Smoking contributes to approximately one in three cancer deaths

It is also a risk factor for cancer of the cervix and vulva, uterus and bowel and acute myeloid leukemia.1

Alcohol appears to potentiate the carcinogenic effect of tobacco, significantly increasing the risks of cancer of the
head and neck, stomach, liver and pancreas.

Overall, cigarette smoking contributes to approximately one in three cancer deaths.

Any exposure to tobacco increases the risk of cancer

At an individual level, the risk of developing cancer is related to the life-time exposure to tobacco, the quantity
smoked each day, the total number of years smoked and the age that smoking started.2 Of all these factors,
the length of time that someone smokes seems to be the most significant. For example in people who have smoked for 45
years the risk of lung cancer is 100 times greater than for individuals who have been smoking for 15 years even if the
amount smoked each day is less.3

There is no safe level of tobacco exposure. There is measureable risk of cancer with low levels of smoking,4,5 occasional
smoking,6 low tar cigarette smoking and passive smoking.7,8

Stopping smoking reduces cancer risk

Stopping smoking reduces the risk of smoking-related cancers. This effect is most pronounced at younger ages but stopping
smoking at any age confers benefit. People who stop smoking at age 30 years reduce their risk to almost that of non-smokers,
those at age 50 years can halve the excess risk of cancer,9 and mortality is even reduced in people who stop
smoking in their seventies.10

The effect of stopping smoking varies depending on the cancer:11

The risk of lung cancer halves in about ten years

The risk of oral and laryngeal cancer takes at least 20 years after stopping to reduce to that of non-smoker

The risk of bladder cancer takes at least 25 years after stopping to reduce to that of non-smoker

It remains controversial as to whether there is any real benefit from cutting down the number of cigarettes smoked each
day.12 However this may be a strategy for those unable to quit completely.13

Lung cancer

Nine out of ten lung cancers are directly related to smoking and the inhalation of second hand smoke is estimated to
be responsible for one in four of the lung cancers found in non-smokers.14

Upper aerodigestive cancer

Smoking is associated with around nine in ten cancers of the lip, oral cavity, pharynx, larynx and oesophagus.15 All
types of tobacco exposure carry a risk of developing these cancers including chewing tobacco, using snuff, smoking cigars
or smoking marijuana as well as the more obvious risk from cigarette smoking.

By the age of 75 a smoker has a one in 16 chance of developing these cancers compared to a one in 125 chance in a non-smoker.16

Stomach and Pancreatic cancer

Smoking contributes to over one in four pancreatic cancers17 and one in five stomach cancers.18

Urinary tract cancers

Smoking increases the risk of bladder cancer by three to five times19 and contributes to two out of three
cases in men and one in three cases in women.

The risk of kidney cancer is doubled by smoking. It contributes to one in four cases in men, and one in ten cases in
women.20

Wakai K, Marugame T, Kuriyama S, et al. Decrease in risk of lung cancer death in Japanese men after smoking cessation
by age at quitting: pooled analysis of three large-scale cohort studies. Cancer Sci 2007;98(4):584-9.

Inequalities in cancer death rates contribute to the significant gap in life expectancy between Māori and non-Māori

There are disparities in access to cancer services

Māori are nearly twice as likely to die from cancer, even though they are only 18% more likely to have cancer.
One reason for this is that Māori are more likely to be diagnosed with cancer at a more advanced stage.

Lung cancer is the leading cause of cancer deaths in New Zealand. The incidence of lung cancer in Māori is the
highest in the world. Lung cancer mortality rates have increased in Māori but have decreased for other ethnic groups.
The average age of death is also lower (63 years compared to 70 years).

New Zealand survival rates from lung cancer are one of the poorest in the developed world. Lung cancer is the leading
cause of cancer deaths with a five year relative survival rate of 10.2%, considerably worse than Australia (12%) and the
USA (15.6%). The five year relative survival rate for Māori is 7.7%.

Early detection and referral of smoking related cancers

Early detection and referral of smoking related cancers

Since the majority of people with cancer will initially present to general practice, GPs have the greatest opportunity
to make a difference with early detection and the initiation of speedy referral to specialist services. However, the difficulty
is to achieve improved cancer detection without increasing unnecessary referrals, which may reduce access to services
for people who need them.

“Lower threshold for referral equals more referral equals more delay to get a hospital appointment. I believe
the key point is the quality of the referrals. Referring patients early may cause more patients with self limiting conditions
to undergo investigations which do more harm than good to them and the health system. The best test we have in general
practice is time BUT we must ensure timely follow up to identify those not resolving”. – GP, Nelson

Detecting cancer

For people presenting with typical symptoms and signs of cancer, the diagnosis and decision for referral is straightforward.
However the initial symptoms of some cancers can be difficult to distinguish from the symptoms of other more common disorders
or may be vague and non-specific.1

General guidelines

In people presenting with atypical symptoms or signs, the presence of a risk factor may increase the suspicion of cancer.
General risk factors that increase the suspicion of cancer include:

Māori or Pacific ethnicity2

Current or ex-smoker

Known exposure to carcinogen e.g. asbestos

Previous personal or family history of cancer

Known pre-cancerous condition e.g. Barrett’s oesophagus

If a person presents three or more times with the same symptom or group of symptoms, the GP needs to exclude cancer.
Referral to a specialist must be considered.3

Combinations of signs and symptoms have a higher predictive value than a single symptom.3

If common symptoms do not resolve as expected, the initial diagnosis should be reviewed and cancer excluded.4

Avoiding delay

Early referral may improve prognosis for people with cancer

Any delay in the time taken from when the first symptom is noticed by the patient, to the start of treatment has potentially
negative consequences on the prognosis of cancer.

Delays can occur at several stages and include:

Failure of some patients to seek help quickly

Difficulties GPs have in identifying patients with cancer5

Administrative delays in secondary care with the referral process,6 accessing investigations and planning

Patient delays

Māori and Pacific peoples,7 older people and those from areas of low deprivation8 are more
likely to be diagnosed with cancer at a more advanced stage9 and may by-pass general practice completely and
present for the first time at the Emergency Department.10 It is appropriate to have a higher degree of clinical
suspicion in these groups and to examine possible barriers to accessing healthcare.

GP delays

Common reasons for GP delay in referring are insufficient examination, initial misdiagnosis of cancer as a benign self-limiting
condition11,12 and failure to organise definite follow up.5

Delays in investigation and referral

People with features typical of cancer need to be referred without delay. GPs should ensure referrals:

Are followed up promptly to ensure there has been no administrative errors in secondary care that may result in delay

Only consider investigations if this will not delay the referral process. In people with less typical symptoms and signs
that might be due to cancer, order investigations urgently.

Making decisions about treatment

Once a possible diagnosis of cancer is made further investigations are required to confirm the diagnosis, stage the
cancer and measure the performance status (general health) of the patient before treatment is commenced. Many of these
investigations are not available in primary care, except privately, and are usually managed after referral to specialist
services.

The cancer diagnosis is usually confirmed with histology or cytology. This is to ensure that the patient does have
a malignancy. The precise histopathology will guide prognosis and influence the choice of treatment. For example treatments
for small-cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) are very different and therefore accurate histological
diagnosis is essential.

Treatment decisions are also based on the stage of the cancer. Staging is based initially on clinical examination but
is usually clarified with imaging such as CT, MRI or PET scans. The general health of the patient and presence of co-morbidities
are also important as they may reflect the prognosis and influence the choice of treatment offered.

Once the information on diagnosis, stage and performance status is available a joint decision can be made between the
patient, their family/whanau and the specialist, on whether treatment to cure the patient will be attempted or to offer
palliative treatment alone.13

Shahid S, Thompson SC. An overview of cancer and beliefs about the disease in Indigenous people of Australia, Canada,
New Zealand and the US. Aust N Z J Public Health 2009;33:109-18.

Spotlight on lung cancer

Spotlight on lung cancer

Lung cancer is the fifth most common cancer in New Zealand after breast, prostate, malignant melanoma and colon. However
it is the leading cause of cancer mortality in New Zealand men (21%) and the second highest cause in women (16.5%).1

Lung cancer is rare before the age of 40, more common in Māori and 90% of people with lung cancer are smokers or
ex-smokers.1,2

New Zealand has the worst survival rates for lung cancer in the developed world.3

Earlier diagnosis and referral can improve survival rates

The biggest influence on survival is the extent of disease at diagnosis. Lung cancer has one of the lowest survival
outcomes of any cancer because over two-thirds of people are diagnosed at a late stage when curative treatment is not
possible.

Identifying risk factors for lung cancer

Smoking is the largest preventable risk factor for lung cancer. The risk is increased further with
smoking related COPD.4

Family history of lung cancer in a first-degree relative is associated with a two-fold increased risk,
independent of smoking.5

Previous smoking related cancer, especially of the head and neck increases the risk developing lung
cancer.6

Previous cancer treatment for Hodgkins and non-Hodgkins lymphoma and testicular cancer has been shown
to increase the risk of lung cancer. The risk is higher in patients who have been treated with radiotherapy, particularly
if they are smokers.7

Identifying symptoms of lung cancer
Making a diagnosis of lung cancer on clinical grounds alone is often not possible. Patients present with a variety
of symptoms, mainly respiratory, that are difficult to distinguish from those of other diseases.10

Red flag symptom – unexplained haemoptysis
Referral for a chest x-ray should be considered in a person presenting with haemoptysis, unless it is the first
presentation in an otherwise asymptomatic young person.The most common symptoms of lung cancer are cough, dyspnoea, weight
loss and thoracic pain. Haemoptysis and bone pain are also relatively common (Table 1, below).6 Screening
individuals without suspicious symptoms is not recommended.11

Occupational exposure to carcinogens

Occupational exposure to carcinogens contributes to 8.5% of lung cancer deaths in New Zealand.8 Occupational
causes should be considered in people who have a relevant work history (Table 1).
N.B. In some cases, treatment may be covered under ACC.

When to refer

A person should be referred urgently for a chest x-ray if they have unexplained haemoptysis or any of the following
unexplained persistent signs and symptoms:11

False negative chest x-rays in people with lung cancer12

Overall, chest x-rays may be reported as normal in one in four patients who are found to have lung cancer. The x-ray
may be reported as normal but falsely negative for cancer:

If the lesion is too small to be identified

If the lesion is hidden behind intra-thoracic structures or the skeleton

If the x-ray is of poor technical quality or is misreported

If clinical suspicion remains, usually as the result of continuing symptoms or the development of new ones, then further
action is warranted. In this situation urgent referral to a specialist for CT scanning and bronchoscopy is recommended.

Chest and/or shoulder pain

Shortness of breath

Weight loss or loss of appetite

Abnormal chest signs

Hoarseness

Finger clubbing

Cervical and/or supraclavicular lymphadenopathy

Cough

Features suggestive of metastasis from a lung cancer

The NZGG define “urgent” referral for chest x-ray as being completed and reported within one week.12

The NZGG define “persistent” signs and symptoms as those lasting more than three weeks or less than three
weeks in people with known risk factors.11

Best practice tip: A person with risk factors for lung cancer who has an x-ray
showing consolidation should have a repeat chest x-ray within six weeks to ensure that this has resolved.

Sputum cytology is not recommended for the investigation of lung cancer, except if the patient is too unwell to undergo
bronchoscopy. False positives are extremely rare so if positive the likelihood that there is cancer is very high. However
it has a very low sensitivity and a negative result cannot be taken to exclude cancer.10

Referral to specialist care
A person should be referred urgently to a specialist if they have:11

Persistent haemoptysis and are smokers or ex-smokers aged 40 years or older

A chest x-ray suggestive of lung cancer

A normal chest x-ray but where there is a high suspicion of lung cancer (see sidebar above)

The case of the tight shirt collar

Recognising superior vena cava obstruction (SVCO)
A 62 year old man presents with a two week history of progressive dyspnoea on exertion, increased snoring and
fatigue. He has noticed that his shirt collars have become tight. He is a current cigarette smoker of 15–20 cigarettes
a day.

Examination reveals the classic signs of SVCO:

Oedema of the face and arms

Flushed face

Cyanosis

Dilated and congested veins over the arms, neck and anterior chest wall

Stridor due to laryngeal oedema

Papilloedema

Dilated veins over the abdomen (collateral circulation has developed)

Headache and confusion due to cerebral oedema

SVCO is a medical emergency and you make an immediate referral to specialist care.

Investigations in primary care are not recommended.

SVCO

SVCO can be due to external pressure or involvement of the vessel by cancer tissue or thrombus. It has mainly malignant
causes - the most common is lung cancer.

The superior vena cava carries blood from the head, neck, arms, and upper chest to the heart. When obstructed, the increased
venous pressure results in facial, neck and /or upper limb swelling.13 Oedema may affect the larynx or pharynx
and cause cough, hoarseness and stridor. Symptoms of cerebral oedema include headache, confusion and coma. Over time a
collateral circulation develops diverting the venous flow through superficial veins.

Other associated symptoms are chest pain, dizziness, disturbed vision, nausea and nasal stuffiness. Symptoms and signs
tend to be aggravated by postures that increase the venous pressure in the upper body such as lying down, bending over
or raising the arms above the head. There may also be symptoms from the underlying aetiology e.g. lung cancer.

Symptoms and signs depend on the speed of onset of the compression and the degree of narrowing. Often the symptoms of
SVCO develop over many weeks, but in approximately one third of patients the symptoms may develop in two weeks or less.
In some cases symptoms improve as collateral circulation develops.

The case of the bloody tissue

A 43 year old woman presents with a one week history of cough and increased sputum production. This is the third
time she had visited with a “bad cold”. On this occasion she has noticed some blood in her sputum, which
has also become green. She is a current smoker of 20 cigarettes per day. She has been struggling to keep her weight up
over the previous few months and relates this to stress at work and the series of “bad colds”.

Examination reveals:

Erythematous throat with no tonsillar exudate

Mild soft submandibular lymphadenopathy

A few scattered rhonchi

Weight loss of 4 kg since last month

There is no tachycardia, fever, cyanosis or finger clubbing. The trachea is central. There are no focal signs in the
chest. Cardiovascular examination is normal.

You should refer for urgent chest x-ray or respiratory assessment.

Haemoptysis

Haemoptysis is the spitting or coughing up of blood that originated in the lungs or bronchi. Patients may be unsure
where the blood is coming from and the first step is to differentiate between haemoptysis, pseudohaemoptysis (spitting
of blood not derived from lungs or bronchi, commonly the nasopharynx) and haematemesis.

Haemoptysis is a common symptom. It occurs in up to 40% of people with bronchitis and is also seen in other less serious
respiratory conditions. However it is a “red flag” symptom for lung cancer, pulmonary tuberculosis, pulmonary
embolism and other serious cardiovascular conditions, as well as systemic diseases and coagulopathies. The likelihood
of lung cancer being the cause of haemoptysis is increased when it is recurrent or persistent, and when accompanied by
other symptoms such as dyspnoea, weight loss and anorexia and signs such as finger clubbing.14

The case of the wife who can’t sleep

A 77 year old man attends surgery for his routine three monthly repeats. He has started coughing at night and
his wife has asked him to get some cough mixture as he is disturbing her sleep. He is only producing a small amount of
sputum that is white in colour. He has no weight loss, fever or night sweats. He would also like a repeat GTN spray as
he has been using this more often for anterior chest pain but thinks it may be “a dud” as it doesn’t
seem to be working as well as usual. He has smoked for 50+ years, and has hypertension, ischaemic heart disease and chronic
kidney disease. His current medications include: low dose aspirin, cilazapril/hydrochlorothiazide MANE, GTN spray PRN,
paracetamol, combivent inhaler 2 puffs QID, beclomethasone inhaler 2 puffs bd.

Examination is unremarkable. Peakflow is 340 L/min, a good result for him. However the history includes two suspicious
features for lung cancer – a new cough and unexplained chest pain which does not appear to be cardiac.

You adopt a stepwise approach to diagnosing the cause of cough.15

You stop ACE inhibitor, check inhaler technique and arrange to review one week later

Cough is still present, the patient is already on bronchodilators so you trial promethazine and omeprazole to exclude
upper airway cough syndrome (UACS) and GORD16 and review one week later

The cough persists so you refer for chest x-ray

Cough is a common symptom of lung cancer but chronic cough is rarely due to malignancy

It is estimated that less than 1% of patients who visit their doctor with persistent cough will have lung cancer.17

The majority of lung cancers present to primary care with common respiratory symptoms.18 The problem for
the GP is to filter out very small number of serious cases that warrant urgent specialist referral for investigation of
a possible cancer. This is difficult because many symptoms that could indicate cancer, such as cough, also have benign
causes and the benign causes are more common.

Acute cough is invariably due to infection or asthma.19 A cough that has continued for more than three weeks
(chronic) is a diagnostic challenge but is still more likely to have a benign cause (Table 2). Apart from current smoking
and ACE inhibitors, the three most common causes of chronic cough are upper airway cough syndrome (UACS, previously known
as postnasal drip syndrome), asthma and gastro-oesophageal reflux disease (GORD).20,21 The timing of the cough
and its character are not predictive of the cause.